The planned schemes include Walmar House and Regent Street in W1, and Fetter Lane in EC4

Great Portland is also in discussions with Crossrail about its plans for Hanover Square W1 while preparation work is almost complete ready for main construction work to start next year at 100 Bishopsgate where the developer has formed a joint venture with main contractor Brookfield.

The update came as the firm announced a £15m pre-tax profit for the six months to September 2010 which is an 11% rise on the same period last year.

Toby Courtauld, Chief Executive, said: “Growth rates in London’s investment markets have slowed, as expected, over the past four quarters.

“Whilst there continues to be a surfeit of buyers over sellers, particularly from overseas, we believe these more sedate conditions will persist into 2011 as the uncertain macro environment will continue to affect sentiment in the short term.

“Looking ahead, we remain confident that London will retain its status as a leading financial centre.

“We continue to be encouraged by the level of tenant demand across our portfolio, and we have delivered another quarter of good letting activity, with solid rental value growth and a consistently low void rate.

“This bodes well for our 1.8 million sq. ft. near term development programme where we expect to start seven schemes during 2011 to add to the four currently on site.”